Some of the conventional optical pickup devices incorporated in the optical disc recorders and/or players are provided with a dust-proof feature to prevent any foreign matter such as dust from adhering to the objective lens.
For example, the optical pickup device with such a dust-proof feature includes an optical pickup mounted on a base to be movable radially of an optical disc, and a moving mechanism to move the optical pickup radially of the optical disc. The optical pickup device also includes a compartment for housing the optical pickup as a whole. In this optical pickup device, when the recorder and/or player is not in use, the moving mechanism is controlled to house the optical pickup into the compartment in order to prevent any foreign matter such as dust from adhering to the objective lens in the optical pickup.
In such a dust-proof feature to house the entire optical pickup in the compartment when the recorder and/or player is not in use, however, the compartment has to be larger in dimensions than the optical pickup, which will require the optical pickup device to have an increased size. Namely, a small optical pickup device cannot use any such dust-proof feature.
Also, since the dust-proof feature is intended primarily for prevention of any foreign matter from adhering to the objective lens, it should only be capable of masking the objective lens without having to house the entire optical pickup.
Also, the recent optical disc as a recording medium can record information signals mode densely. Accordingly, the recent optical pickup uses an objective lens having a larger numerical aperture and thus the distance between the optical disc and objective lens is shorter. Therefore, when the optical disc is moved into or from inside the compartment, the objective lens will possibly touch with the inner surface of the compartment and be scratched. Once the objective lens is thus scratched, information signals cannot accurately be read from or written to the optical disc.